The purification and filtration of water and other aqueous solutions is necessary for many applications, such as the treatment of feeds, waste streams, process streams and by-products associated with various industrial processes, the provision of safe portable drinking water, and the treatment and control of municipal waste water. Known methods for purifying aqueous solutions include reverse osmosis, distillation, ion-exchange, chemical adsorption, coagulation, flocculation, and filtering or retention. Many of these purification practices can be costly, energy inefficient and require significant technical know-how and sophistication to implement on both large and small scales. As a result, many advanced fluid purification technologies have had limited application.
There remains a need for improved removal methods (in terms of, for example, efficiency and selectivity) for removing anions, such as phosphate, from water. The improved methods would desirably contain an active composition stable to decomposition (i.e., a composition that neither bleeds into surrounding water, nor decomposes to form a harmful substance). The disclosure that follows describes such methods and compositions for removing anions, such as phosphate, from water.